Tomato (Solanum lycopersicum Mill. cv. Belladona F1) plants were either self-rooted, self-grafted, or grafted onto the commercial rootstocks “Beaufort”, “He-Man”, and “Resistar” and grown in a recirculating hydroponic system. Three nutrient solutions differing in NaCl-salinity level (2.5, 5.0, and 7.5 dS m–1, corresponding to 0.3, 22, and 45 mM NaCl) were combined with the five grafting treatments in a two-factorial (3 × 5) experimental design. At the control NaCl level (0.3 mM), fruit yield was not influenced by any of the grafting treatments. However, at low (22 mM NaCl) and moderate (45 mM NaCl) salinity levels, the nongrafted and the self-grafted plants gave significantly lower yields than the plants grafted onto He-Man. The plants grafted onto the other two rootstocks gave higher yields only in comparison with the nongrafted plants, and the differences were significant only at low (Beaufort) or moderate (Resistar) salinity. Yield differences between grafting treatments at low and moderate salinity arose from differences in fruit number per plant, while mean fruit weight was not influenced by grafting or the rootstock. NaCl salinity had no effect on the yield of plants grafted onto He-Man but restricted the yield in all other grafting treatments due to reduction of the mean fruit weight. With respect to fruit quality, salinity enhanced the titratable acidity, the total soluble solids, and the ascorbic acid concentrations, while grafting and rootstocks had no effect on any quality characteristics. The leaf Na concentrations were significantly lower in plants grafted onto the three commercial rootstocks, while those of Cl were increased by grafting onto He-Man but not altered by grafting onto Beaufort or Resistar in comparison with self-grafted or nongrafted plants. Grafting onto the three tested commercial rootstocks significantly reduced the leaf Mg concentrations, resulting in clear Mg-deficiency symptoms 19 weeks after planting.
Agriculture in India, having seen rapid strides in 80's, is at a cross road, with stagnating crop yields despite increased use of fertilisers and increasing cost of cultivation. Besides several factors responsible for such a situation, one major reason seems to be lack of information and effective communication - the last mile delivery of available farm technology, in a location specific manner, and poor use efficiency of most of the agri-inputs. This calls for coveted improvement in the quality of technical information and its last mile delivery. This paper describes various aspects of last mile delivery and approaches to overcome the situation, especially thorough Public Private Partnership (PPP). A suitable working model of PPP with targeted and result oriented approach is also suggested.
Recommendations for amount of fertilizer N, P and K to obtain optimum yields of rice and wheat in different states in the Indo-Gangetic plain show hardly any similarity in terms of ratios of applied N:P2O5:K2O. Even when nutrient needs are based on crop removal and fertilizer use efficiency considerations, nutrient ratios do not have any relevance. In fact, there is hardly any relationship between nutrient ratios and food production or the pattern of NPK removal by crops. The deviation from the commonly recognized ratio of N:P2O5:K2O as 4:2:1 in administration circles and bias towards applying urea as compared to P and K to both rice and wheat is conspicuously visible in the ratios observed in different parts of the Indo-Gangetic plains. The data generated from long-term fertility experiments revealed that responses to N, P and K or partial factor productivity values for N, P and K were not found to be related in any manner with the N:P2O5:K2O ratios. In this paper relevance of N:P2O5:K2O ratios in fertilizer recommendations has been critically analysed in the context of fertilizer use on a field to region scale for achieving balanced supply of NPK as well as sustainable high yield levels of rice and wheat.
December 2010
English
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