Sarcotesta, sclerotesta, endosperm and embryo of fresh and old (0 and 3 years, respectively) seeds of the P.R. 6-65 and P.R. 8-65 papaya varieties were separately analyzed by paper chromatography to determine the presence of natural growth inhibitor that might be responsible for the reduction in germination of papaya seeds during storage. The results showed that in the innermost seed parts (embryo and endosperm) endogenous growth promoters were found while the outermost structures (sarcotesta and sclerotesta) contained inhibitors. Therefore, it is possible that the natural growth inhibitors of this seed might be minimized by removing the sarcotesta (the gelatinous envelope) of the seed, which contains the most endogenous growth inhibitors, plus a careful washing to eliminate the soluble inhibitors of the sclerotesta during the extraction of seeds from the fruits.
An experiment was designed to determine the yield, water use and nutrient uptake of a tomato (Lycopersicon esculentum Mill. cv. Rambo) crop grown on coconut dust substrate using fertigation, without re-utilization of drained nutrient solution. The density was 2 plants m-2 , with 11 litres of substrate per plant. The total yield was 19.9 kg m-2 , the marketable yield 15.9 kg m-2 and the average marketable fruit weight 210.2 g. The total nutrient solution provided during growth period was 736.8 mm, the drainage loss came to 219.4 mm and, thus, the crop water use average 517.4 mm. In the growth period, the irrigation frequency varied from 3, at the beginning of growth, to 14 irrigations per day, during the period of maximum water requirement, the amount of water changing from 0.3 to 6.6 mm per day. The drainage losses fluctuated between 18% and 30.5%, and the electric conductivity between 3 and 6 dS m-1. Nutrient uptake by the crop (in g.m-2) was: 65.1 N,
Plantas de soja, cv. Santa Rosa e cv. UFV-1 foram cultivadas em solução nutritiva até a produção de vagens quando foram colhidas e analisadas. A variedade Santa Rosa mostrou-se menos exigente em N, P, K, Ca, Mg, Cu, Fe, Mn e Zn; a exigência de S foi igual e a de Cl maior que a da cv. UFV-1.
A sand culture greenhouse experiment was conducted with Carica papaya L., variety Blue Solo, to determine the effects of five (14, 28, 56, 112 (control) and 224 p/m) levels of nitrogen in the nutrient solution on the growth, fruiting and nutrient content. Nitrogen deficiency symptoms are described. Mineral content of blades, petioles and fruit are presented and discussed. The papaya has a high N requirement, (probably higher than the highest level of 224 p/m we supplied). Plant height, nodes in the stem, trunk diameter, leaf fresh and dry weights, total yield (fruits harvested) and fruit quality increased as the N supply was increased. Critical N level in the blade and petiole appears to be about 4 and 2%, respectively. Quality components of the fruits are discussed, based on a panel evaluation. Fruits from the lower N supply levels were of poorer flavor.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.