In experiments with post-germinal embryo cultures of the soya varieties McCall and Eszter, the isolated embryos were incubated in modified 85 nutrient medium. Over a three-week period, rooting was almost 100 per cent. The various auxins examined did not stimulate root formation. The addition of 2 g/l active carbon to the nutrient medium promoted the development of a normal root system. Ca 30 per cent of the seedlings planted out can be raised. These plants flower and fruit earlier, having a shorter life cycle. Considerable differences can be observed between the varieties examined, particularly in shoot formation, which is more intense in the McCall variety.

India has discovered an unfortunate consequence of the Green Revolution: high yielding varieties are suffering from micro nutrient deficiencies Recent research indicates that most crops cultivated with Green Revolution material and techniques show alarming deficiencies of trace elements such as zinc and iron, which is a serious obstacle to high-quality food production. Zinc enables plants to absorb nitrogen whilst phosphorous andiron promote the synthesis and maintenance of chlorophyll. Zinc deficiency can reduce rice yields by 0.16 to 3.9 tonnes per hectare wheat yields by 0.01 to 1.98t/ha and maize yields bv 0.06 to 3.4t/ha. Micro-nutrient deficiencies also affect human and animal health. In staple foods, zinc deficiency can lead to retarded growth in children. As far as livestock are concerned, the lack of zinc also results in retarded growth or parakeratosis as well as bone and joint problems. Trying to restore the deficiency of one particular micro-nutrient by supplying a chemical supplement often proved inadequate and costly. Traditional farming systems may provide easier and more appropriate solutions, such as multiple cropping with leguminous plants and the addition of organic manure. Research conducted at the Punjab Agricultural University has shown that the addition of simple farm manure is effective in counteracting these deficiencies. Traditional techniques can still prove to be of considerable value. | India has discovered an unfortunate consequence of the Green Revolution: high yielding varieties are suffering from micro nutrient deficiencies Recent research indicates that most crops cultivated with Green Revolution material and techniques show...

Foi feito um experimento, em casa de vegetação com quatro cultivares de sorgo sacarino: CMS x S 603, Br 500, Sart e Br 602, usando-se solução nutritiva de Hoagland e Arnon nº 1 modificada para a solução padrão contendo os tratamentos (níveis de Al, P, K). Colhido o material e determinado os pesos da matéria seca da raiz e parte aérea e os teores dos elementos P, K, Ca, Mg e Al, verificou-se que: a) ocorreu estímulo na produção de matéria seca de alguns cultivares por determinadas combinações de níveis de Al e nutrientes; b) o acréscimo dos níveis de K no substrato promoveu um aumento na tolerância ao Al desde que o P estivesse em alta concentração; c) o fornecimento de K em nível muito alto (solução de Hoagland e Arnon(, não permitiu diferenciar cultivares quanto ao grau de tolerância; d) os teores dos elementos Ca, Mg, K, P e Al na parte aérea dos cultivares foram diferentes para os mesmos, quando comparados os tratamentos que acarretaram as maiores e menores produções de matéria seca. | Four sweet sorghum varieties (CMS x S 603,Br 500, Sart and Br 602) were grown in a modified Hoagland's solution in order to supply varying levels of Al, P and K. Dry matter production was measured. The material was analysed for P, K, Ca, Mg and Al. The following conclusions could be drawn: a) a stimulation on growth of some varieties was observed when a given combination among Al and other nutrient levels was provided; b) by increasing K level in the nutrient solution more tolerance to Al toxicity was observed, as long as P was present in high concentration in the substrate; c) a high level of K in the nutrient solution, such as thal given in Hoagland's solution, does not allow to differentiate cultivars with respect to tolerance to Al toxicity; d) there were differences among varieties with respect to tissue P,K, Ca, Mg and Al concentrations wich were associated with maximum and minimum growth.

Increased removal of soil nutrients by increased cropping of high yielding cereal varieties and grain legumes together with reduced financial returns from cropping are discussed in relation to new technology developed to ensure adequate nutrient replenishment. The efficient use of fertilizers is emphasized and based on new technology for accurately predicting requirements of nitrogen, phosphorus, trace elements and the use of high analysis fertilizers; the cost-price squeeze on fertilizer recommendations is an important aspect. The important role of legumes is discussed in relation to nitrogen fixation and the availability of this nitrogen to cereal crops. The use of new tools for recognizing nutrient stress is mentioned together with precautions necessary to ensure their correct application.

An experiment on 42 dairy cows from 6 to 105 days of lactation was carried out. The rations with concentrate feeds partially replaced by untreated or formaldehyde treated whole soya beans, or rapeseed of 2 varieties were fed. Feeding of whole soya beans or rapeseed resulted in increasing milk yield and milk fat content. Lower nutrient digestibility coefficients in cow fed formaldehyde treated whole soya bean and rapeseed meals were stated

La investigacion se realizo en Villa Nueva, Guatemala. Su objetivo fue evaluar el rendimiento de 4 variedades de brocoli (Brassica oleracea italica) con caracteristicas para exportacion y evaluar la respuesta del cultivo a la aplicacion de abonos organicos e inorganicos. Las variedades utilizadas fueron: Green Duke, Emperor, Commander y Experimental-90 y como fuentes de nutrientes se utilizo gallinaza, estiercol bovino, 15-15-15 y 16-20-0. Se utilizo diseno bloques al azar con arreglo de parcelas divididas, con 4 repeticiones. Los resultados mostraron diferencia significativa solamente para peso de inflorescencia, de donde las variedades Green Duke, Emperor y Experimental-90 rindieron menos (8,395; 9,234 y 7,605 kg/ha respectivamente) con aplicacion de gallinaza son recomendables para su cultivo en la region y otras zonas con caracteristicas similares.

Soil compaction increased soil penetration resistance. High soil penetration resistance decreased root growth in deeper soil profiles (15- to 40-cm soil depths). With sufficient water (300 mm) and nutrient supply, soil compaction increased nutrient (NPK) uptake and upland rice yield. Otherwise, at 30 mm water, it decreased root growth and, consequently, reduced yield. Potassium at 75 kg/ha reduced the ill-effects of drought and soil compaction. Drought stress also increased soil penetration resistance, more in compacted than in noncompacted soils, and bulk density. It decreased shoot and root growth, NPK uptake, leaf water potential and grain yield more than did soil compaction. Total root nutrient uptake, however, was influenced more by soil compaction than by drought stress. Soil compaction and drought stress both decreased root respiration rate. Potassium application in nutrient-deficient acid soils increased root growth in deeper soil profiles, resulting in increased nutrient uptake and grain yield. Root growth decreased with soil depth due to increasing soil penetration resistance. Available nutrients also decreased with soil depth. However, root growth at various soil depths was positively correlated with grain yield. Varietal differences in K response was observed in Leyte. Crop yield was twice of the control (0 kg K/ha) with 25 kg K/ha. At 50 kg K/ha, yield of UPLRi-7 during the second cropping increased four times. Root growth and grain yield in Leyte [Philippines] are improved by K nutrition. Higher grain yield was observed in Batangas compared to Leyte site because of more fertile soil and higher weekly solar radiation. Under favorable conditions, genetic characteristics can be well expressed, thus, significant varietal differences in grain yield was observed in Batangas. Results at farmers' field experiments suggest that upland rice yield was influenced by site, variety, and K fertilizer. Grain yield can be increased by planting varieties with high yield potential and which are highly responsive to applied nutrient, and by proper timing of cropping season