scholarly journals A New Curve of Critical Leaf Potassium Concentration Based on the Maximum Root Dry Matter for Diagnosing Potassium Nutritional Status of Sweet Potato

2021 ◽  
Vol 12 ◽  
Author(s):  
Zunfu Lv ◽  
Guoquan Lu
Keyword(s):  
Nutritional Status ◽  
Sweet Potato ◽  
Dry Matter ◽  
Field Experiments ◽  
Growth Period ◽  
Nutrient Concentrations ◽  
Growth Stages ◽  
Application Rates ◽  
Maximum Root ◽  
K Concentration

Critical leaf nutrient concentrations have often been used to diagnose the nutritional status of crops. Determining critical leaf potassium (K) concentrations for the maximum root dry matter (RDM) will provide a reliable means of linking leaf K nutrient concentrations to the yield of sweet potato. Three field experiments, using varying K application rates (0–300 kg K ha−1) and two sweet potato cultivars, were performed in the Zhejiang Province of China. A new critical leaf K curve (Kleaf) based on the maximum RDM was determined to assess K nutrition in sweet potato and described by the equation Kleaf=4.55×RDMmax-0.075. A critical root K curve (Kroot) based on the maximum RDM was also determined to assess K nutrition and described by the equation Kroot=2.36×RDMmax-0.087. The K nutrition index (KNI) was constructed to identify the situations of K-limiting and non-K-limiting treatments. The leaf KNI (KNIleaf) ranged from 0.56 to 1.17, and the root K KNI (KNIroot) ranged from 0.52 to 1.35 during the growth period of sweet potato. The results showed that the critical leaf K concentration curve can be used as an accurate leaf K status diagnostic tool at critical growth stages that connected leaf nutrient concentration and sweet potato tuber yield. This K curve will contribute to K management of sweet potato during its growth period in China.

Effect of silicon at panicle initiation on the growth of rice (Var. ADT-36) plants at different growth stages

2002 ◽  
Vol 50 (2) ◽  
pp. 179-184
Author(s):  
P. M. Arthanari ◽  
P. Gnanamoorthy ◽  
S. Ramasamy
Keyword(s):  
Tamil Nadu ◽  
Dry Matter ◽  
Field Experiments ◽  
Dry Matter Production ◽  
Growth Stages ◽  
Maturity Stage ◽  
Maturity Stages ◽  
Matter Production ◽  
Initiation Stage ◽  
Different Growth Stages

Field experiments were conducted at Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, India during the Rabi (November 1997-March 1998) and Kharif (July 1998-November 1998) seasons to identify the effect of silicon at panicle initiation on the growth of rice plant (Variety ADT-36) at different growth stages. Furnace slag was applied as a silicon source at 2 t/ha at the panicle initiation stage along with other nutrients. The dry matter production was recorded at the active tillering, panicle initiation, booting, flowering, one week after flowering and maturity stages in both the seasons. The total dry matter production was greater in the Kharif season than in the Rabi season. The application of slag at the panicle initiation stage along with N and K at the flowering stage had a significant influence over the dry matter production. A similar trend was observed in both the seasons. The silicon uptake was recorded at the panicle initiation and maturity stages. About 30-40% of the silicon absorbed during the early stages and the maturity stage was present in the shoot, whereas 20-30 % of the silicon absorbed during the maturity stages was present in the leaf blades. Based on the results, it is concluded that the supply of silicon during the panicle initiation stage is most important for plant growth.

SENSITIVITY OF CROP PLANTS TO WATER STRESS AT SPECIFIC DEVELOPMENTAL STAGES: REEVALUATION OF EXPERIMENTAL FINDINGS

1995 ◽  
Vol 43 (2) ◽  
pp. 99-111 ◽  
Author(s):  
Zvi Plaut
Keyword(s):  
Water Stress ◽  
Irrigation Water ◽  
Field Experiments ◽  
Developmental Stages ◽  
Growth Period ◽  
Soluble Solids ◽  
Growth Stages ◽  
Mild Stress ◽  
Uniform Reduction ◽  
Different Growth Stages

It has been suggested that in many crops differences in sensitivity to water stress occur at different growth stages. Since identical amounts of water may be applied, irrespective of whether a crop is exposed to relatively severe and short periods of stress or to extended periods of mild stress, the responses to such differing conditions should be compared. Unfortunately, such a comparison has not been conducted in most studies on sensitivity to water stress at different growth stages. In the present study, based on three field experiments conducted for different purposes, such a comparison was made for three crops: corn, sunflower, and tomato. In corn, distinct responses of ear and kernel yields to the timing of water stress were found. Withdrawal of irrigation water during flowering and cob formation resulted in greater yield losses than during other stages, indicating that this is a critical growth stage. However, slight and uniform reduction of water during the entire growth period resulted in significantly less damage to kernel or ear production, although the total amount of water applied was similar to that under staged withdrawal. In sunflowers, the withdrawal of irrigation water even at noncritical growth stages caused a more marked reduction in grain yield than did a uniform reduction throughout the entire season. In tomatoes, on the other hand, the withdrawal of irrigation water during specific growth stages caused minimal damage to fruit and total soluble solids yield as compared with fully irrigated control; reduction of irrigation water throughout the season brought about a significant decrease in yield. The difference between these crops is interpreted on the basis of the determinance of their floral meristems.

Nutrient status of sugar cane in relation to leaf nutrient concentration

1968 ◽  
Vol 8 (34) ◽  
pp. 606 ◽  
Author(s):  
ICR Holford
Keyword(s):  
Sugar Cane ◽  
Field Experiments ◽  
Leaf Tissue ◽  
Growth Period ◽  
Nutrient Status ◽  
Maximum Growth ◽  
Nutrient Concentrations ◽  
Ratoon Crop ◽  
Nutrient Levels ◽  
Leaf Nutrient Levels

The nitrogen, phosphorus, and potassium requirements of sugar cane were studied in relation to the concentration of these elements in the leaf tissue of three varieties of sugar cane grown commercially in Fiji. Percentage yields of sugar cane in fertilizer field experiments were highly correlated with leaf nutrient levels in the control plots, provided leaf sampling was carried out during the maximum growth period of mid- January to mid-May. For each nutrient there was a marginal zone of leaf concentration below which crops always gave significant yield responses to applied nutrients and above which crops failed to respond. Marginal zones for crops sampled during mid-March to mid-May were 1.4-2.0 per cent for nitrogen, 0.13-0.21 per cent for phosphorus, and 0.9-1.5 per cent oven dry leaf for potassium. Within the deficient range of leaf nutrient concentrations there was little relationship between optimum rates of fertilizer required to correct the deficiency and leaf nutrient levels of unfertilized cane. Because of the lateness of sampling, any indication of fertilizer requirement would only be applicable to a subsequent ratoon crop.

INFLUENCE OF SHADE ON STOMATAL DENSITY, LEAF SIZE AND OTHER LEAF CHARACTERISTICS IN THE MAJOR TROPICAL ROOT CROPS, TANNIA, SWEET POTATO, YAM, CASSAVA AND TARO

2000 ◽  
Vol 36 (4) ◽  
pp. 509-516 ◽  
Author(s):  
I. C. ONWUEME ◽  
M. JOHNSTON
Keyword(s):  
Sweet Potato ◽  
Ipomoea Batatas ◽  
Dry Matter ◽  
Field Experiments ◽  
Alley Cropping ◽  
Stomatal Density ◽  
Cropping Systems ◽  
Leaf Size ◽  
The Other ◽  
Lower Epidermis

Since shading often occurs under normal growing conditions in various cropping systems (for example, intercropping, alley cropping), field experiments were carried out to determine the effects of shading on stomatal density, leaf size, leaf dry matter, and leaf lamina thickness in the major tropical root and tuber crops, tannia (Xanthosoma sagittifolium), sweet potato (Ipomoea batatas), yam (Dioscorea esculenta), cassava (Manihot esculenta), and taro (Colocasia esculenta). Shading decreased stomatal density in the lower epidermis of tannia, sweet potato, yam and cassava, and in the upper epidermis also in tannia and sweet potato; the upper epidermis of yam and cassava were devoid of stomata. In contrast to the other species, taro under shade had an increased stomatal density in both the upper and lower epidermis, a finding which was confirmed in subsequent pot experiments. This response of taro was postulated as a possible manifestation of greater shade adaptation by the species.For all the species, shading generally resulted in the production of larger (in terms of surface area) but thinner leaves, with a decreased dry matter concentration. For the two species (yam and cassava) that had stomata only on the lower epidermis, normal sun-grown plants had about twice as many stomata per unit area of lower epidermis than did corresponding plants of the other three species. The agronomic and physiological significance of the findings are discussed.

scholarly journals Influences of water deficiency on the productivity of young plants at different sites

2018 ◽  
pp. 371-378
Author(s):  
Katalin Sárdi
Keyword(s):  
Crop Production ◽  
Production Efficiency ◽  
Field Experiments ◽  
Nutrient Supply ◽  
Limiting Factors ◽  
Nutrient Concentrations ◽  
Growth Stages ◽  
Water Deficiency ◽  
Negative Effects ◽  
Site Characteristics

Water deficiency has become one of the most limiting factors of crop production in Hungary as the tendency in annual amounts of precipitation shows a decreasing tendency; therefore, it has become similar to those of Southern Europe. The most significant decrease in precipitation occurs typically during spring, approximately 20% of the data expressed in the averages of the last century. Studying the relationship between water deficiency as a stress factor and nutrient supply is important in order to improve the production efficiency of crops. Nowadays, this problem receives outstanding attention presented in numerous papers both in Hungary and globally, however, there are several questions yet to be answered. Our pot experiments were carried out under controlled greenhouse conditions in order to establish new data on these relationships. Experimental soils were typical for Western Transdanubia, taken from long-term field experiments representing four different site characteristics of the region. It was concluded from the results that drought periods during the early growth stages (i.e. 4–5 weeks after emergence) of plants may result in significant decreases in both dry matter production, nutrient concentrations, nutrient uptake and shoot:root ratios. Better nutrient supply, especially potassium, plays a significant role in reducing the negative effects of water deficiency.

Effects of soil drought during the generative development phase on seed yield and nutrient uptake of faba bean (Vicia faba)

1997 ◽  
Vol 48 (4) ◽  
pp. 447 ◽  
Author(s):  
M. Z. Xia
Keyword(s):  
Vicia Faba ◽  
Seed Yield ◽  
Faba Bean ◽  
Seed Weight ◽  
Dry Matter ◽  
Nutrient Concentration ◽  
N Uptake ◽  
Nutrient Concentrations ◽  
Soil Drought ◽  
K Concentration

The effects of periods of drought during different phases of reproductive growth of faba bean (Vicia faba L.) cv. Xichang Dabai were investigated in a pot experiment at Xichang Agricultural College, China. Parameters were total dry matter; seed yield; yield components; concentrations of nitrogen, phosphorus, and potassium; and total uptake in different organs. All drought treatments decreased total dry matter production and seed yield per plant. Plants subjected to drought from initiation of pod-set to full pod-set (stage D4) produced 32% less total dry matter and 45% less seed yield than the irrigated control. Mean seed weight was a relatively stable yield component. Statistical analysis indicated that only plants subjected to drought at stages D4 and D5 (drought from full pod-set to maturity) had a significantly (P < 0·05) lower mean seed weight than the control. The nutrient concentration was generally high in the younger or more active organs of faba bean, and comparing the nutrients, the N concentration in leaves, stems, flowers, pods, and grain was greatest, followed by K concentration, and P concentration was least. All soil drought treatments decreased the nutrient concentration in various organs after 17–19 days of drought. However, the decreases at maturity were less clear, except the nutrient concentrations in stems and leaves. Water deficit significantly decreased total grain nutrients per plant, the decreases being 34–45% for N uptake, 34–47% for P uptake, and 33–46% for K uptake. Simple linear correlations with the P and K concentration in leaves at maturity and number of pods and seeds per plant gave a correlation coefficient (r) of 0·804–0·874.

Growth Stage-Influenced Differential Response of Foxtail and Pigweed Species to Broadcast Flaming

2010 ◽  
Vol 24 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Santiago M. Ulloa ◽  
Avishek Datta ◽  
Stevan Z. Knezevic
Keyword(s):  
Weed Control ◽  
Dry Matter ◽  
Growth Stage ◽  
Field Experiments ◽  
Growth Stages ◽  
Weed Species ◽  
Common Waterhemp ◽  
Species Response ◽  
Redroot Pigweed ◽  
Green Foxtail

Propane flaming could be an effective alternative tool for weed control in organic cropping systems. However, response of major weeds to broadcast flaming must be determined to optimize its proper use. Therefore, field experiments were conducted at the Haskell Agricultural Laboratory, Concord, NE in 2007 and 2008 using six propane doses and four weed species, including green foxtail, yellow foxtail, redroot pigweed, and common waterhemp. Our objective was to describe dose–response curves for weed control with propane. Propane flaming response was evaluated at three different growth stages for each weed species. The propane doses were 0, 12, 31, 50, 68, and 87 kg ha−1. Flaming treatments were applied utilizing a custom-built flamer mounted on a four-wheeler (all-terrain vehicle) moving at a constant speed of 6.4 km h−1. The response of the weed species to propane flaming was evaluated in terms of visual ratings of weed control and dry matter recorded at 14 d after treatment. Weed species response to propane doses were described by log-logistic models relating propane dose to visual ratings or plant dry matter. Overall, response of the weed species to propane flaming varied among species, growth stages, and propane dose. In general, foxtail species were more tolerant than pigweed species. For example, about 85 and 86 kg ha−1were the calculated doses needed for 90% dry matter reduction in five-leaf green foxtail and four-leaf yellow foxtail compared with significantly lower doses of 68 and 46 kg ha−1of propane for five-leaf redroot pigweed and common waterhemp, respectively. About 90% dry matter reduction in pigweed species was achieved with propane dose ranging from 40 to 80 kg ha−1, depending on the growth stage when flaming was conducted. A similar dose of 40 to 60 kg ha−1provided 80% reduction in dry matter for both foxtail species when flaming was done at their vegetative growth stage. However, none of the doses we tested could provide 90% dry matter reduction in foxtail species at flowering stage. It is important to note that foxtail species started regrowing 2 to 3 wk after flaming. Broadcast flaming has potential for control or suppression of weeds in organic farming.

scholarly journals Genotypic variation for potassium accumulation and utilization efficiency in barley under rainfed potassium stress conditions

2003 ◽  
Vol 51 (3) ◽  
pp. 267-280 ◽  
Author(s):  
Y. S. Shivay ◽  
J. H. Chen ◽  
S. R. Ding
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Stem Elongation ◽  
Genotypic Variation ◽  
Utilization Efficiency ◽  
Growth Stages ◽  
Potassium Accumulation ◽  
Yield Increase ◽  
Plant Parts ◽  
K Concentration

A field experiment was carried out to study the effect of K nutrition and genotypic variation on the dry matter (DM) accumulation, and the K concentration, accumulation, uptake and utilization efficiency in barley (Hordeum vulgare L.). Successive increases in potassium nutrition had a significant effect on the dry matter and K accumulation either in the total or in various plant parts of barley at the tillering, stem elongation, heading and maturity growth stages. K nutrition also led to significantly higher grain yield with each unit K application than without K application. The yield increase due to K application was mainly due to the improvement in spike development from tillers. Dry matter and K accumulation in various plant parts varied significantly between genotypes at the main growth stages. Among the various plant parts, the stem contained the highest K concentration, had the highest K accumulation at maturity and changed considerably with the K level, while other plant parts remained relatively unchanged. Among the eleven genotypes, genotype 98-6 had the highest grain yield and the K use efficiency of this genotype was 10.4 kg grain per kg K applied. It could thus be used as a breeding line to breed barley varieties for higher productivity under rainfed conditions with low available soil potassium.

Efficacy of increasing application rates and combination of herbicides and mowing at different growth stages of common teasel (Dipsacus fullonum)

2020 ◽  
pp. 1-27
Author(s):  
Juan F. F. Daddario ◽  
Guillermo Tucat ◽  
Osvaldo A. Fernandez ◽  
Diego J. Bentivegna
Keyword(s):  
Field Experiments ◽  
Growth Stages ◽  
Invasive Weed ◽  
Leaf Stage ◽  
Additional Information ◽  
Application Rates ◽  
The Impact ◽  
North And South America ◽  
North And South ◽  
Different Growth Stages

Abstract Common teasel is a troublesome invasive weed in North and South America. Additional information on the efficacy of herbicide application and mowing at different growth stages will help in common teasel management. Firstly, an outdoor pot experiment was performed to assess increasing application rates and combinations of glyphosate and 2,4-D amine, when applied at four leaf, rosette and bolting stages. Secondly, field experiments were performed to evaluate the impact of time of cutting on invasive common teasel plant height, head number, and head length. Finally, germinability of seeds collected from naturally growing plants was determined to evaluate the feasibility of mowing invasive common teasel after flowering. Only glyphosate applied at 1.08 kg ae ha-1 at four leaf stage provided adequate control (>90%). Although control was not satisfactory (<90%) when applying glyphosate at 2.16 kg ae ha-1 at rosette and bolting stages, and 2,4-D at 1.75 kg ae ha-1 at four leaf stage, significant injury and biomass decline were observed. Glyphosate and 2,4-D combinations did not improve common teasel control compared with single applications. Cutting rosettes strongly reduced inflorescence production (34-42%) and cutting flowering plants prevented total regrowth. Germination of seeds averaged 14% when harvested 10 d after flowering, and maximum seed germination (>90%) was found 30 d after flowering. Glyphosate applied alone at the recommended commercial rate early in the growing season together with cutting at the flowering stage, may be the most beneficial way of controlling invasive common teasel.

scholarly journals Evaluation of Diagnostic Technologies for Assessing the N Nutritional Status of Lettuce

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 519A-519
Author(s):  
C.A. Sanchez ◽  
M. Wilcox ◽  
J.L. Aguiar ◽  
K.S. Mayberry
Keyword(s):  
Nutritional Status ◽  
Field Experiments ◽  
Plant Biomass ◽  
Aerial Photographs ◽  
Growth Stages ◽  
Canopy Reflectance ◽  
N Nutrition ◽  
Iceberg Lettuce ◽  
Nitrate N ◽  
Diagnostic Technologies

Twenty field experiments were conducted to evaluate the response of iceberg lettuce (Lactuca sativa L.) to N and evaluate various diagnostic technologies as tools for assessing the N nutritional status of lettuce. Lettuce yields showed a curvilinear response to N in most experiments. Generally, the dry midrib nitrate-N test and the sap nitrate-N test appear to be sensitive indicators of the N nutritional status of lettuce after the folding stage of growth. The chlorophyll meter was not a sensitive indicator of the N nutritional status of lettuce. Preliminary data also show that canopy reflectance, including digital analysis of aerial photographs, is correlated to N nutritional status of lettuce. However, reflectance technologies do not readily distinguish between N deficiencies and other factors (insects, diseases, water stress, etc.) that affect plant biomass and color. Because plant tests do not appear to be sensitive indicators of N nutrition during early growth stages (before folding), a post-thinning (and pre-sidedress) soil nitrate-N test is currently being evaluated.

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