Enhancing floral and habitat diversity for augmenting natural enemies 
in rice ecosystem of Thanjavur, Tamil Nadu, India

Field experiments on "Enhancing floral and habitat diversity for augmenting natural enemies in Thanjavur rice belt" was conducted during kharif (2017 and 2018) and rabi (2017). In habitat diversified rice crop, the main crop of rice was maintained along with flowering vegetation in field bunds viz., cowpea, green gram, black gram, sunflower, gingelly, bhendi, cluster bean, maize and marigold. Weeds mainly from Umbelliferae, Leguminosae and Compositae that support natural enemies were also maintained adjacent to rice bunds. Non-crop habitat included straw heaps on rice bunds. Daincha was planted in rogue spacing and bird perches installed to encourage both the natural enemies and insectivorous birds. The mean value of insect pest population was about 56 per cent lower in habitat diversified rice crop (7.39 insects /5 sweeps) than that of pure rice crop (16.87 insects /5 sweeps). In the case of mean value of natural enemy population, habitat diversified rice crop (26.74 individuals /5 sweeps) recorded two times higher population than that of pure rice crop (13.40 individuals /5 sweeps). In habitat diversified rice crop the pest-defender ratio was high in all the periods of observation compared to pure rice crop. The mean pest:defender ratio was 1: 3.74 in habitat diversified rice crop as compared to 1: 0.89 in pure rice crop. The mean grain yield recorded was 4.99 t/ha in habitat diversified rice crop as compared to 4.36 t/ha in pure rice crop. In habitat diversified rice crop, the per cent increased grain yield recorded over pure rice crop ranged from 10.43 to 21.18.Crop diversification and non-crop habitats certainly encouraged natural biological control by supplementing food resource and shelter. Over the years complex food web would persist leading to sustainable and ecofriendly insect pest management in rice ecosystem.

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Fertility investigations on the black earth wheatlands of the Darling Downs, Queensland. III. Mineral nitrogen in the soil and its relation to the wheat crop

Australian Journal of Agricultural Research ◽

10.1071/ar9600027 ◽

1960 ◽

Vol 11 (1) ◽

pp. 27 ◽

Cited By ~ 6

Author(s):

SA Waring ◽

LJH Teakle

Keyword(s):

Grain Yield ◽

Ammonia Nitrogen ◽

Mean Value ◽

Mineral Nitrogen ◽

Wheat Crop ◽

Nitrogen Accumulation ◽

A Value ◽

The Mean ◽

The One ◽

Growing Crop

The level of mineral nitrogen in the soil under fallow and crop was measured for the years 1951 to 1953. Relationships of mineral nitrogen at planting to yield and nitrogen content of wheat grain and straw were examined. Values for nitrate nitrogen at the end of the fallow period ranged most commonly from 10 to 20 µg/g in the surface 2 ft and from 0 to 10 µg/g at 2-4 ft. Approximately one-third of the sites showed an increase from the third to the fourth foot. One site showed extremely high values throughout the profile, particularly at 3-4 ft where a value of 127 µg/g was recorded. Values for ammonia nitrogen were most commonly in the range of 0-3 µg/g . Under the growing crop, mineral nitrogen declined for most depths in the period from planting up to September or October, after which there was little further change to harvest. Uptake of mineral nitrogen was normally greatest from the surface 2 ft of soil. Below 3 ft there were two groups of sites. One group showed moderate to high uptake and the second group low uptake. The low uptake in the latter group provides a reason for mineral nitrogen accumulation below 3 ft at some sites. Mineral nitrogen to 4 ft at planting averaged 126 lb/ac, excluding the one site with exceptionally high values. This was double the mean value of 63 lb/ac for nitrogen recovered in grain and straw, for crops planted in May-June. These figures, combined with trends in the soil under crop, suggest that most of the nitrogen used by the crop was derived from that in the soil at planting. Correlations between mineral nitrogen at planting and grain yield were mostly non-significant, suggesting that in general nitrogen was not an important factor limiting yield. Low grain yield and protein percentage were recorded at a number of sites which had been cultivated more than 50 years.

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Change in Maize Final Leaf Numbers and Its Effects on Biomass and Grain Yield across China

Agriculture ◽

10.3390/agriculture10090411 ◽

2020 ◽

Vol 10 (9) ◽

pp. 411

Author(s):

Wanmao Liu ◽

Bo Ming ◽

Ruizhi Xie ◽

Guangzhou Liu ◽

Keru Wang ◽

...

Keyword(s):

Grain Yield ◽

Field Experiments ◽

Climatic Factors ◽

Input Parameter ◽

Climatic Conditions ◽

Leaf Number ◽

Maize Crop ◽

Area Index ◽

Distribution Ranges ◽

The Mean

The final leaf number is an important morphological characteristic of maize (Zea mays L.) and is therefore an important input parameter in some maize crop models. In this study, field experiments were conducted from 2013 to 2016 at 23 sites across China, which were located between latitudes of 26°30′ and 46°45′ N, focusing on five modern maize cultivars, in order to determine the amplitude of variation in mean leaf numbers between each cultivar, identify differences between the mean leaf numbers of cultivars under different climatic conditions, and clarify the effects of the differences in final leaf numbers on aboveground dry matter (DM) and grain yield. The results showed that the mean final leaf numbers increased in the order of XY335 < NH101 < ZD909 < ZD958 < DH11 among the five cultivars, with the wide distribution ranges of final leaf numbers being 17.0–23.3 (DH11), 16.7–22.3 (ZD958), 16.7–22.0 (ZD909), 16.7–22.3 (NH101), and 17.0–22.0 (XY335) across all locations. In addition, leaf numbers above and below the primary ear showed the same trends with the mean final leaf numbers for the same cultivars. Many climatic factors were found to significantly affect the final leaf numbers across four maize-growing regions in China, and the result of stepwise regression indicated that the influences of photoperiod and temperature, in particular, were greater than other climatic factors for these cultivars. Finally, there were found to be significant and positive relationships between the final leaf number and (1) the maximum leaf area index (LAImax), (2) DM at both silking and physiological maturity, and (3) grain yield for the same cultivars across all locations. The results of this study are of great importance for guiding future trans-regional maize cultivation and further model calibration.

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Soil temperature and its association with maize yield variations in the Highlands of Kenya

The Journal of Agricultural Science ◽

10.1017/s0021859600028288 ◽

1977 ◽

Vol 89 (2) ◽

pp. 355-363 ◽

Cited By ~ 9

Author(s):

P. J. M. Cooper ◽

R. Law

Keyword(s):

Soil Temperature ◽

Grain Yield ◽

Growth Rates ◽

Dry Matter ◽

Strong Relationship ◽

Maize Yield ◽

Moisture Stress ◽

Early Growth ◽

Mean Value ◽

The Mean

summaryIn the Highlands of Kenya every 1-week delay in planting maize after the onset of the rains reduces the grain yield by approximately 0·6 t/ha. No satisfactory explanation has been found for this phenomenon. A physiological growth study was made on four dates of planting per year over 4 years. Early growth rates and maximum crop growth rates showed a progressive decline with delay in planting which resulted in smaller plants at 5 weeks post-emergence and at 50 % tassel emergence in maize planted later. There was a strong relationship between the size of plant at tasselling and the final grain yield and a highly significant relationship (r = 0·94) between the size of plant at 5 weeks post emergence and the final grain yield. Other environmental studies showed that soil temperature at 7·5 cm, coupled with a soil moisture stress factor, largely controlled the dry-matter production rate during early growth, and consideration of the mean value of these two variables over the first 5 weeks of growth accounted for 70% of the variation of dry matter at 5 weeks post-emergence. It was further shown that 82% of the variation in final grain yield caused by date of planting could be accounted for by consideration of the mean value of these two variables during the first 5 weeks of growth.

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Impact of maize cob and wood-derived biochar on soybean plant growth and soil aggregate structure in dry land

10.5194/egusphere-egu2020-13007 ◽

2020 ◽

Author(s):

Hua Ma ◽

Qirui Li ◽

Sonoko D. Bellingrath-Kimura

Keyword(s):

Plant Growth ◽

Grain Yield ◽

Soil Structure ◽

Clay Soil ◽

Soil Aggregate ◽

Mean Value ◽

Soybean Plant ◽

Aggregate Structure ◽

Dry Land ◽

The Mean

Soil structure plays important roles in land degradation, soil fertility, and agricultural productivity and thus has great ecological importance. Soil aggregation is a crucial soil function for maintaining soil porosity and enhancing the stability of soil structure to prevent soil erosion. Biochar was reported to be a binding agent for organic matter in aggregate formation and thus alleviate aggregates degradation. Therefore, this study attempts&#160;to a) investigate the impact of the biochar on soybean plant growth, plant nutrients content and soil chemical properties; b) analyze the effect of maize cob biochar (CB) and wood biochar (WB) on soil aggregate structure in vulnerable dry land area.Field trial was performed on two sandy soil fields (at MLZ and BDG village)&#160;and one loamy clay soil field (at RQ village) which located in Ningxia, China. Two treatments (20 t ha-1&#160;of CB&#160;and WB application) and control were repeated 7 times. In this study, we analyzed biomass, grain yield, and nutrients content of soybean plant while soil nutrients&#160;were&#160;observed as well. Nine soil aggregate size classes (ASCs) were obtained&#160;(>10, 10-7, 7-5, 5-3, 3-2, 2-1, 1-0.5, 0.5-0.25 and <0.25 mm)&#160;through&#160;dry sieving to analyze soil structure.&#160;In addition, soil dry mean weight diameter (dMWD), dry geometric mean diameter (dGMD), and structure coefficient (Ks) were measured&#160;to estimate the aggregate stability, erodible fraction, and agronomically valuable fraction. After that, redundancy analysis and ridge regression analysis were applied for further data processing.Our results&#160;indicated&#160;a)&#160;biomass&#160;and&#160;grain&#160;yield:&#160;both CB and WB significantly increased shoot biomass in loamy clay soil by 48.7% and 45.0%, respectively. In the two sandy soils, biochar indicated no significant enhancement on the plant growth and grain yield. Even though, the mean value of grain yield&#160;increased by 29.7% and 35.1% with the CB and WB application in the MLZ field, respectively. CB application also increased the mean value of&#160;grain yield by 34.2% in the BDG field. Although the data&#160;shows insignificant difference with high standard errors due to field heterogeneity,&#160;the mean values&#160;can&#160;still give insights&#160;into&#160;agricultural field practices;&#160;b)&#160;soil&#160;aggregate&#160;structure:&#160;soil type exerted stronger influence on soil aggregation and plant growth rather than biochar.&#160;The sandy field in MLZ showed high soil loss potential by wind erosion referring&#160;to a&#160;low value of dGMD, and the loamy clay field showed the highest dMWD, dGMD and Ks values&#160;for&#160;an ideal aggregate structure for crop growth. Findings indicate that biochar had no significant influence on aggregate structure in both sandy and loamy clay soils;&#160;c) soil&#160;nutrients:&#160;CB can significantly increase&#160;soil total carbon content in RQ and BDG fields. Soil potassium content can be&#160;enhanced by CB application in loamy clay soil.

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RATOONED LOWLAND NERICA RICE VARIETIES AS AN OPTION FOR TRIPLE CROPPING IN INLAND VALLEYS OF DERIVED SAVANNAH IN NIGERIA

Experimental Agriculture ◽

10.1017/s0014479712000452 ◽

2012 ◽

Vol 48 (4) ◽

pp. 551-562 ◽

Cited By ~ 4

Author(s):

S. O. ADIGBO ◽

M. O. OLOJEDE ◽

P. J. C. HARRIS ◽

O. AJAYI

Keyword(s):

Grain Yield ◽

Field Experiments ◽

Block Design ◽

Appropriate Technology ◽

Lowland Rice ◽

Rice Crop ◽

Rice Varieties ◽

Fluted Pumpkin ◽

Inland Valley ◽

Cropping Seasons

SUMMARYAlthough triple cropping in inland valleys of Nigeria is technically feasible, the third crop between the main crop and dry season non-rice crop has been considered not to be economically viable because of poor crop establishment due to soil inundation. The identification of an appropriate technology with low input, such as ratooning, would allow this niche to be utilized. Field experiments were conducted at the University of Agriculture, Abeokuta, Nigeria in 2007–2008 and 2008–2009 cropping seasons to evaluate the performance of the main and ratooned crops of lowland NERICA (New Rice for Africa) rice (Oryza sativa L.) varieties in a lowland rice–ratooned rice–fluted pumpkin (Telfairia occidentalis Hook F.) sequence. The experiment was laid out in a randomized complete block design with three replicates. The lowland rice varieties used were NERICA-L 19, NERICA-L 20, NERICA-L 22, NERICA-L 24, OFADA, NERICA-L 26, NERICA-L 41, NERICA-L 42, NERICA-L 44 and NERICA-L 47. The grain yield of the main rice crop ranged from 5.0 to 7.3 t ha−1 in 2007–2008 cropping season and from 4.1 to 9.1 t ha−1 in 2008–2009. The ratooned rice had a grain yield of 1.0–4.7 t ha−1 in 2007–2008 and 1.2–3.4 t ha−1 in 2008–2009. The total grain yield obtained in 2007–2008 from the main and ratooned rice crops in seven months was 6.7–11.6 t ha−1, while in 2008–2009 it was 5.3–2.6 t ha−1. The fresh leaf yield of fluted pumpkin ranged from 14.6 to 16.9 t ha−1 in 2007–2008 and from 18.3 to 19.8 t ha−1 in 2008–2009, similar to previously reported rainy season unfertilized yields. Thus, a ratooned rice crop appears to be a feasible technology capable of boosting rice production and consequently increasing the overall productivity of the inland valley in a rice–rice–vegetable cropping sequence.

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Relationship between scald (Rhynchosporium secalis) and losses in grain yield of barley in Western Australia

Australian Journal of Agricultural Research ◽

10.1071/ar9850655 ◽

1985 ◽

Vol 36 (5) ◽

pp. 655 ◽

Cited By ~ 7

Author(s):

TN Khan ◽

MF D'Antuono

Keyword(s):

Grain Yield ◽

Critical Point ◽

Western Australia ◽

Field Experiments ◽

Yield Loss ◽

Growth Stages ◽

Point Model ◽

Percentage Yield ◽

The Mean ◽

Ripe Stage

The three commonly used techniques, viz. critical point model, area under the curve and multiple linear regression, were applied to study the relationship between scald infection and grain yield in field experiments conducted during 1979-1983 in Western Australia. In the preliminary analysis leaf three from the top and the mean of the top three leaves were found to be best correlated with yield. The three models did not dilfer greatly, presumably owing to the high correlations between scald at the milky ripe stage and at the earlier growth stages. The critical point model was chosen because of its simplicity. Percentage yield loss in combined data from all experiments showed a significant correlation (P < 0.001) with scald at the milky ripe stage and defined percentage yield loss in cultivars Clipper and Stirling to be about one-third of the mean scald damage on leaves 1 (flag), 2 and 3 at g.s. 75. Due to the range of trials in this analysis, it was suggested that this relationship may be applied to estimate yield loss from survey data in other parts of southern Australia, where scald is endemic.

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B73 and related inbred lines in maize breeding

Genetika ◽

10.2298/gensr0503245s ◽

2005 ◽

Vol 37 (3) ◽

pp. 245-252 ◽

Cited By ~ 1

Author(s):

Milisav Stojakovic ◽

Goran Bekavac ◽

Nenad Vasic

Keyword(s):

Grain Yield ◽

Inbred Lines ◽

Mean Value ◽

Yield Potential ◽

Maize Breeding ◽

Serbia And Montenegro ◽

Maize Hybrids ◽

Hybrid Production ◽

The Mean ◽

Per Se

Inbred lines B73 and Mol7 or some versions thereof are the most commonly used parental pair in the development of medium late and late maize hybrids in Serbia and Montenegro. Because of the ever-increasing importance of line B73 in maize hybrid production, we chose several B73-type lines and a few unrelated lines and crossed them. Using the pedigree method, progenies were developed up to the S6 generation. The grain yield potential of test crosses with Mo 17 inbred tester, as well as ear length, number of grain rows per ear and 1,000-grain mass of lines per-se were tested. Among the new inbred lines related to B73, line 260277/2 distinguished itself by a high potential for grain yield when crossed with Mo 17. Inbred lines 260465/1, 260362/1, 260747/4, 260357/13, 260151/2 and 260156/2 had a significantly longer ear than the mean value of all progenies. Compared with progeny mean, lines 260341/7, 260317/4, 260277/2 and 260187/2 had significantly more grain rows per ear, while 260362/1, 260130/5, 260277/2, 260151/2 and 260187/2 had a significantly larger 1,000-grain mass.

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Performance of Pre Released Rice (Oryza sativa L.) Genotypes under Different Sowing Windows in Rabi Season

International Journal of Environment and Climate Change ◽

10.9734/ijecc/2020/v10i1030248 ◽

2020 ◽

pp. 43-51

Author(s):

D. Anil ◽

Sreedhar Siddi

Keyword(s):

Grain Yield ◽

Field Experiments ◽

Agricultural Research ◽

Oryza Sativa L ◽

Rice Crop ◽

Growth And Yield ◽

Yield Potential ◽

Research Station ◽

Net Returns ◽

Sowing Dates

The aim of this study was to investigate the effect of different sowing dates on growth and yield potential of pre released rice genotypes under irrigated conditions of Northern Telangana zone. The field experiments were carried out during two consecutive rabi seasons of 2018-19 and 2019-20, on clay soils of agricultural research station, Kunaram, Telangana state, India. The experiment was laid out in strip plot design with three replications. The treatments comprised of three sowing dates i.e. 20th November, 5th December and 20th December in horizontal factor and four genotypes i.e. KNM 733, RNR 15048, KNM 1638 and KNM 118 in vertical factor. Pooled data analysis results revealed that the different sowing dates and genotypes significant effect on all the studied growth and yield characters. The rice crop sown on 20th December recorded significantly higher grain yield ( 8138 kg ha-1) and Among the genotypes, the short slender, short duration genotype KNM 733 recorded the recorded the maximum grain yield ( 8024 kg ha-1), which was on par with the other genotypes. The treatment combinations data results concluded that the, among the genotypes the genotype KNM 118 was recorded highest grain yield (8438 kg ha-1) when sowing was taken up on 20th December and followed by the genotype KNM 733 with sown on 20th November. In respect of economics of treatment combinations, the highest net returns (Rs.91,165 ha-1) and B:C (2.47) ratio were obtained when rice crop was sown during 20th December with the genotype KNM 118 and followed by sown on 20th November with the genotype KNM 733.

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Drought resistance in spring wheat cultivars. I. Grain yield responses

Australian Journal of Agricultural Research ◽

10.1071/ar9780897 ◽

1978 ◽

Vol 29 (5) ◽

pp. 897 ◽

Cited By ~ 727

Author(s):

RA Fischer ◽

R Maurer

Keyword(s):

Grain Yield ◽

Field Experiments ◽

Water Status ◽

Cultivar Differences ◽

Yield Potential ◽

Severe Drought ◽

Yield Data ◽

Wide Range ◽

The Mean ◽

Yield Responses

With a view to understanding the basis of cultivar differences in yield under drought, a wide range of cereal cultivars representing durum wheats (Triticum turgidum L.), triticales (X Tritosecale Wittmack), barleys (Hordeum vulgare), and especially tall and dwarf bread wheats (T. aestivum L.) were studied in field experiments in north-western Mexico over three seasons. Drought was created in this rain-free environment by permanently terminating irrigation at various stages before anthesis. Control treatments were well watered throughout the growing period. Detailed measurements of plant water status, leaf area and dry matter production, anthesis date, yield components and grain yield were made. This paper presents primarily the grain yield data. Drought levels were such that the mean yield of all cultivars under drought ranged from 37 to 86% of control yield, corresponding to irrigation cut-offs varying from 69 days before mean anthesis date to only 10 days before. In each experiment the grain yield under drought showed highly significant cultivar differences, which appeared consistent between years. Yields were adjusted for drought escape by using a correction factor which ranged from 2.9 to 8.5 g/m2 per day advance in flowering, being greater in experiments with less severe drought. The demonstration of linear relationships between cultivar yield and drought intensity, as indicated by the mean yield of some or all cultivars, prompted the consideration of cultivar yield under drought as the function of yield potential (Yp, yield without drought), drought susceptibility index (S), and intensity of drought. The cultivar groups showing lowest S values (most droughtresistant) were tall bread wheats and barleys; dwarf bread wheats were intermediate, and durum wheats and triticales were the most susceptible. However, because dwarf wheats have a higher yield potential (Yp) than tall bread wheats, it is suggested that, as a group, tall bread wheats would outyield dwarf wheats only under very severe drought. Also there was considerable within-group variability of S and Yp. Cultivar S values were consistent across experiments. Yield responses of tall and dwarf bread wheat groups obtained in these experiments agreed with those seen in extensive international trials under dryland conditions.

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The Effect of Varieties and Degree of Ripeness to Vitamin C Content in Tomato Fruits

Acta Horticulturae et Regiotecturae ◽

10.1515/ahr-2017-0010 ◽

2017 ◽

Vol 20 (2) ◽

pp. 44-48

Author(s):

Magdaléna Valšíková-Frey ◽

Patrik Komár ◽

Marián Rehuš

Keyword(s):

Vitamin C ◽

Field Experiments ◽

Mean Value ◽

Average Amount ◽

Tomato Fruits ◽

Green State ◽

Green Fruit ◽

The Mean

Abstract Nine selected varieties of tomatoes were grown in field experiments in order to follow up changes in the content of vitamin C, depending on the degree of the fruit ripeness. Vitamin C content of green fruit ranged from 6.74 mg (Denár) to 10.23 mg (Salus). The mean value for the varieties in the green state was 8.66 mg.100 g−1. The value of vitamin C in the semi-mature tomatoes ranged from 11.34 mg (Denár) to 14.95 mg (Darinka). The mean value for all varieties was 12.89 mg. 100 g−1. The lowest content of vitamin C was found in consumer (red) ripening tomato varieties Šejk (16.03 mg), Denár (16.32 mg) and Zámčan (16.80 mg) and the highest content of vitamin C in varieties Salus (19.43 mg) and Darinka (19.26 mg). The mean value for the nine varieties was 17.70 mg.100 g−1. In the botanical (overripe) maturity, we recorded the highest vitamin C content in the variety Salus (21.51 mg. 100 g−1). The highest increase in vitamin C was also recorded at the variety Darinka, where we registered the content of 21.32 mg.100 g−1. The lowest vitamin C content in botanical ripeness was observed in the variety Zámčan (19.44 mg.100 g−1). The average amount of vitamin C marked 20.26 g mg.100−1. The results can be concluded that the level of vitamin C is increasing by the gradual ripening of the fruits.

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