scholarly journals The effect of quality of food source on macadamia nut damage by Gymnandrosoma aurantianum (Lepidoptera: Tortricidae)

Author(s):  
Helga Blanco-Metzler ◽  
Allan D. Watt ◽  
Derek Cosens

The effect of nitrogen content, the secondary compounds (tannin and proanthocyanidin) content, the dry matter content of 4 clones, and the different developmental stages of macadamia nuts, on the abundance of Gymnandrosoma aurantianum, was studied. Nitrogen content differed between clones and the stages of development of the nuts, being highest in the most tolerant clones 508>660>344>246. Highest dry matter contents were found in the tolerant clones, 508 and 660, and in the outer layer, than in the susceptible clones 246 and 344 and in the inner layers (2 and 3). Proanthocyanidin content was highest in layer 2 of clones 508 and 660 than in clones 246 and 344. Results show that food quality affects the performance of nutborer larvae, where the larvae have to overcome first a physical barrier, followed by a chemical barrier, to be able to feed on macadamia nuts.

Plant Disease ◽  
2021 ◽  
Author(s):  
Yi Wu ◽  
Yicheng Wang ◽  
Jiaxiu Sun ◽  
Yuling Liu ◽  
SHRESTHA SUJATA ◽  
...  

China is the origin and distribution center of kiwifruit, as well as the country with the largest cultivated area and output of kiwifruit. A previous study found that a new kiwifruit virus, Actinidia yellowing ringspot virus (AYRSpV), has been detected in kiwifruit samples with yellowed leaves. The incidence of this virus was high in kiwifruit plantings in Shaanxi Province. To determine the symptoms of this viral infection and the effects of this virus on the yield and quality of kiwifruits, we measured leaf chlorophyll levels and the fruit yield, total sugar, total acid and dry matter contents of ‘Hayward’ kiwifruits grafted with AYRSpV-infected scions. The results showed that after AYRSpV infection, symptoms including chlorotic ringspots were mainly observed in the spring and gradually recovered with high summer temperatures. A few of the leaves that did not recover showed symptoms of albinism, which lasted until the leaves fell. We found that AYRSpV infection could reduce the chlorophyll content of ‘Hayward’ kiwifruit by 74.61-76.64%, the fruit yield by 14.50-24.10%, the sugar to acid ratio by 50.09-50.57%, and the fruit dry matter content by 1.67-1.78%. Our results showed that AYRSpV infection could significantly affect the yield and quality of ‘Hayward’ kiwifruit.


Author(s):  
J. Racskó ◽  
J. Nagy ◽  
Z. Soltész ◽  
M. Soltész ◽  
P. T. Nagy ◽  
...  

The aim of the present study was to determine the effect of nitrogen supply on yield and fruit quality of apple cultivars and to explore the relationships between canopy density and the different fruit quality parameters. The experiments were carried out at Kálmánháza, in Eastern Hungary in a private orchard in 2003-2004. The response of four apple cultivars ('Elstar', 'Gala Prince', 'Granny Smith', 'Idared') to different nitrogen dosages was studied. The assessed and calculated indices were: yield, fruit diameter, fruit height, shape index, fruit mass, firmness, dry matter content and colouration. The results indicated that nitrogen fertilization has a significant effect on the yield and fruit quality of apple cultivars. The calculated specific yield values were reduced by the application of nitrogen via the increase in the volume of the canopy. An opposit trend was observed for fruit diameter, fruit height and fruit weight, which increased with increasing nitrogen supply. The reduced shape index caused flattening of fruits. However, the improvement of fruit quality via increasing nitrogen dosage is only virtual, since these dosages increase the fruit size, but firmness, dry matter content and colouration are diminished, which decreases the value of the fruits on the market. The authors also studied the relationships between canopy density responsible for assimilation and light supply of the fruits and the different fruit quality parameters. The closest linear inversely proportional relationship was found in the case of colouration. There was a negative linear relationship between canopy density and firmness or dry matter content. The relationship between canopy density and fruit mass could be described by a quadratic polinomial function.


2021 ◽  
Vol 51 (3) ◽  
pp. 407-415
Author(s):  
C.R. Schneider ◽  
M.A. Zambom ◽  
D. Galhardo ◽  
A. Faccenda ◽  
A.S. Avila ◽  
...  

This study evaluated silages made with varying proportions of viticulture by-products (VC) and starch extraction from cassava (CSE). It attempted to determine the effects of these proportions on the microbial population, fermentative losses, and chemical composition. The treatments were specified as the proportions of VC in the silage (0 g/kg, 250 g/kg, 500 g/kg, 750 g/kg, and 1000 g/kg). Silages were  evaluated before (0) and after 1, 3, 7, 15, 30, and 60 days of ensiling. The experimental design was completely randomized with five  treatments, six storage times and four replications. The increased level of VC in the silage enhanced its dry matter content, ammonia  nitrogen (NH3-N), and buffering capacity, and reduced organic matter content. Fifteen days after ensiling, additional VC increased the concentration of soluble carbohydrates. The increased level of VC decreased the count of Clostridium spp. and lactic acid bacteria (LAB). The incidence of yeasts and enterobacteria was low in all treatments at all time points. Over time, losses as effluent and gases increased. Use of increasing proportions from VC in silage made with CSE increased the contents of dry matter and soluble carbohydrates and  reduced the fermentative losses of the silage. The increased amount of VC also favoured pH reduction and reduced the proliferation of undesirable yeasts, while increasing the population of LAB.


2019 ◽  
pp. 115-119
Author(s):  
Tímea Rubóczki ◽  
Mária Takácsné Hájos

An increasing interest has been observed of beetroot leaf as a salad component due to recent studies focusing on their nutritional value. The randomized field experiment was carried out on lowland chernozem soil with 6 varieties, 3 replications and 2 sowing dates. Sampling was performed on 23 of August 2018 at the stage of 30 and 50 days of vegetation, where leaf (30 and 50 days) and root (50 days) were collected. Total dry matter, folic acid and nitrate content were evaluated. The results of this investigation show that higher total dry matter content was measured in the root (8.47–10.30%) compared to the leaf in both developmental stages (6.47–9.20%). Nevertheless, higher folic acid content was found in the young leaves of 30 and 50 days of development (58.77–113.86 µg 100g-1). Among the examined varieties, Bonel has presented great amount of folic acid not only in the leaves (99.35–113.61 µg 100g-1), but also in the root (89.99 µg 100g-1). Finally, lower nitrate content was found in Libero (316.16 mg kg-1) at 30 days and in Akela (340.41 mg kg-1) at 50 days of development. Thereby, fresh consumption of beetroot leaves are highly recommended.


1992 ◽  
Vol 118 (2) ◽  
pp. 215-221 ◽  
Author(s):  
F. Pimpini ◽  
L. Giardini ◽  
M. Borin ◽  
G. Gianquinto

SUMMARYPoultry manure and mineral fertilizers at two rates of application (medium and high) and in different combinations, together with a non-fertilized control, were tested at the Experimental Station of the Agricultural University of Padova, Italy (45° 21′ N, 11° 58′ E) in 1985–89.Compared to the control, all the fertilization treatments increased the incidence of larger-sized bulbs of onion and tubers of potato, improved the fruit colour of processing tomato and the raw protein content of spinach, but reduced the acidity and acids: soluble solids ratio of tomato and the dry matter content of spinach leaves.In addition, the application of 140 kg/ha of N, 140 kg/ha of P2O5 and 100 kg/ha of K2O as mineral fertilizer or as poultry manure gave the best scores of processing suitability of potato, both for sticks and chips. All the fertilization formulae, except for 140 kg/ha of N, 140 kg/ha of P2O5 and 100 kg/ha of K2O as poultry manure alone, showed significant decreases in the extractable sucrose ratio in sugarbeet, compared with the control. In processing tomato, the best scores of suitability for paste transformation were obtained with mixed fertilization (1/3 poultry manure and 2/3 mineral fertilizers) applying 210 kg/ha of N, 210 kg/ha of P2O5 and 150 kg/ha of K2O and the plots receiving only mineral fertilizers produced fruits with less favourable values of pH and electrical conductivity compared to the poultry manured ones.


2001 ◽  
Vol 2001 ◽  
pp. 88-88 ◽  
Author(s):  
I.A. Bouriako ◽  
H. Shihab ◽  
V. Kuri ◽  
J. K. Margerison

Wilting grass before ensiling has become a firmly established practice, since it provides economic advantages due to the increment of the dry matter content of the forage before ensiling. Most forage crops contain less than 20 per cent of dry matter when they are cut thus reduction of the weight of crop to be transported provides advantages (Gordon et al., 1999). Also, research has shown that such practices yield improved and reduced effluent loss from the silo and higher feeding value of the silage. Wilting of grass prior to ensiling has been widely adopted as a means of reducing effluents produced and improving the fermentation quality of silage. The aim of this research was to assess the effect of differing wilting periods and silage moisture levels of silage quality and microbial growth levels.


1984 ◽  
Vol 64 (3) ◽  
pp. 593-598 ◽  
Author(s):  
G. W. ATLIN ◽  
R. B. HUNTER

Three autotetraploid maize synthetics were compared with four diploid synthetics of similar adaptation in yield trials and growth analysis experiments at several southern Ontario locations, in order to assess the potential of tetraploid maize as a source of forage. No differences were observed among ploidy levels in productivity of whole-plant dry matter, or in nutritional quality of forage. Tetraploids appeared to be lower in dry matter content at harvest and through much of their period of growth.Key words: Silage corn, forage corn, autotetraploid, (Zea mays L.)


1983 ◽  
Vol 66 (11) ◽  
pp. 2434-2437 ◽  
Author(s):  
A.B. Bodine ◽  
G.D. O’Dell ◽  
M.E. Moore ◽  
C.K. Wheat

1946 ◽  
Vol 36 (3) ◽  
pp. 207-213 ◽  
Author(s):  
H. G. Wager

The dry-matter content of about 260 samples of potatoes was determined. The samples were collected over three seasons and from many types of soil.The average dry-matter content of a variety varied from season to season, but it always bore an approximately constant relationship to the average value of other varieties.Wet seasons led to potatoes low in dry matter.The variation in the content of dry matter of potatoes in different seasons and from different soil types is not a direct effect of the water balance of the tubers.The average content of dry matter of potatoes depends on the soil in which they were grown; fen and blackland gave potatoes with the lowest dry matter, followed by skirt, silt and warp, then loam and medium loam, then clay, and the highest dry matter occurred in stocks grown in sands, gravels or light loams.The difference between the soils is discussed, and it is tentatively concluded that the factor responsible for the variation in content of dry matter of the potatoes is the available water content of the soils.


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