Effect of supplemental Ca2+ on NaCl-stressed castor plants (Ricinus communis L.)

Greenhouse experiments were conducted to assess the effects of supplemental Ca2+ in salinised soil on germination and plant growth response of castor plant (Ricinus communis L. Var. Avani-31, Euphorbiaceae). NaCl amounting to 390 g was thoroughly mixed with soil of seven lots, of 100 kg each, to give electrical conductivity of 4.1 dS m–1. Further, Ca(NO3)2 × 4H20 to the quantity of 97.5, 195, 292.5, 390, 487.5, and 585 g was separately mixed with soil of six lots to give 1:0.25, 1:0.50, 1:0.75, 1:1, 1:1.25, and 1:1.50 Na+/Ca2+ ratios, respectively. The soil of the seventh lot contained only NaCl and its Na+/Ca2+ ratio was 1:0. Soil without addition of NaCl and Ca (NO3)2 × 4H20 served as control, with a 0:0 Na+/Ca2+ ratio. Salinity significantly retarded seed germination and plant growth, but the deleterious effects of NaCl on seed germination were ameliorated and plant growth was restored with Ca2+ supply at the critical level (1:0.25 Na+/Ca2+ ratio) to salinised soil. Supply of Ca2+ above the critical level further retarded seed germination and plant growth due to the increased soil salinity. Salt stress reduced N, P, K+ and Ca2+ content in plant tissues, but these nutrients were restored by addition of Ca2+ at the critical level to saline soil. In contrast, Na+ content in plant tissues significantly increased in response to salinity, but significantly decreased with increasing Ca2+ supply to saline soil. The results are discussed in terms of the beneficial effects of Ca2+ supply on the plant growth of Ricinus communis grown under saline conditions

Salinidade e temperatura na germinação e vigor de sementes de mutambo (Guazuma Ulmifolia Lam.) (Sterculiaceae)

Este trabalho teve como objetivo avaliar a germinação e o vigor de sementes e plântulas de mutambo em resposta à salinidade e a diferentes temperaturas. O experimento foi realizado em laboratório onde as sementes foram colocadas em placas de Petri com soluções salinas de KCl, NaCl e CaCl2 nos potenciais osmóticos de 0,0 (testemunha); -0,4; -0,8; -1,2; -1,6; -2,0 MPa acrescidas (CE) ou não (SE) de espermidina (100ppm). As sementes foram incubadas em BOD, nas temperaturas de 15, 20, 30 e 35ºC. Para cada sal, o delineamento experimental foi inteiramente casualizado, com três repetições de 20 sementes. Não houve germinação na temperatura de 15ºC. Para os três sais ,os valores para porcentagem de germinação foram maiores a 30ºC. Os valores do índice de velocidade de germinação (IVG) diminuíram com a redução dos potenciais osmóticos (PO). O IVG e a massa fresca (MF) apresentaram maiores médias na temperatura de 30ºC. A relação raiz/ parte aérea foi significativamente maior na temperatura de 20ºC, não diferindo significativamente entre CE e SE. Os valores de MF de sementes CE reduziram-se com a diminuição dos PO. Os maiores valores de massa seca (MS) ocorreram a 30 e 35ºC nos tratamentos com KCl e NaCl e a 30ºC com o CaCl2. Não houve diferença significativa na interação entre sal e potencial osmótico para a massa seca. Nas condições controladas deste estudo, Guazuma ulmifolia apresentou germinação e crescimento de plântula em ambiente com salinidade de -2,0MPa e temperatura em torno de 30ºC, não apresentando limite de tolerância até essa concentração em nenhum dos sais avaliados

Seasonal variations in the water quality, diversity and population ecology of intertidal macrofauna at an industrially influenced coast

Present communication reports the physico-chemical and biological quality of seawater and status of benthos of a highly industrialized shore of the north-western coastline of India. The coastal area considered for the present study, encircled by a variety of industries, was divided into two sampling sites and monitored for two consecutive years. Results of the water quality suggest that the obtained values of the physical and chemical parameters of seawater were comparable with data reported earlier. However, data obtained in the biological parameters of the seawater showed a declining trend. Results of the intertidal macrofaunal diversity studies revealed that the muddy upper littoral zones were represented by few species of coelenterata, porifera, arthropoda and mollusca. In the rocky—muddy middle littoral zones, gastropods, stars fishes, corallites, crabs, polychetes and tubeworms were present, whereas, predominantly rocky lower littoral zones were comparatively rich in macrofaunal diversity with small patches of coral colonies. However, when the results obtained in the present study was compared with that of earlier reported data, it was clear that the macrofaunal diversity indeed declined considerably over the years. This may be due to habitat destruction and habitat alteration in the coastline caused by increased anthropogenic activities in the area. Seasonal variations in the population density and abundance were observed in most of the faunal groups except in sessile corals and sponges. This may be due to local migration of the faunal groups towards deeper regions of the Gulf, as supported by the analysis of similarity, to avoid influx of freshwater during monsoon, and high temperature during summer and post monsoon seasons. The overall assessment of different parameters of this study revealed that though the physico- chemical characteristics of the seawater did not varied much from the earlier reported status, the biological characteristics of the seawater and intertidal zone was affected possibly by a high degree of anthropogenic pressure.</jats:p

Effect of Various Organic and Inorganic Formulations on Fruit Setting and Yield in Mango cv. Kesar

The present experiment was carried out at Fruit Research Station, Sakkarbaugh, Department of Horticulture, College of Agriculture, Junagadh Agricultural University, Junagadh (Gujarat). The results of the study indicated that the spraying of monopotassium phosphate 2 % + Boron 0.8 % + Panchgavya 3 %&nbsp; was found effective in fruit setting where as spraying of KNO3 2 % + NAA 50 ppm + Jeevamrut&nbsp; 5 % exhibited the minimum fruit drop at marble stage (58.89 %), harvest stage (49.44 %), maximum fruit retention (48.89 %), maximum number of fruits per panicle (2.08), maximum number of fruits per tree (88) and highest fruit yield (13.57 kg/tree and 3.76 t/ha)