Nutritional effects on transplant root and shoot growth - A review

Transplant growth in the greenhouse can be regulated to a large extent by n utrient levels in the fertilizer solution. Nitrogen has been the target of most nutritional research on transplants, and has long been recognized to h ave the greatest affect on transplant growth. The forms of nitrogen in the nutrient solution also appears important in relation to transplant growth. Increases in phosphorous levels in the nutrient solution do not influence t ransplant growth as dramatically as nitrogen, with little or no response on ce optimum levels are reached. Varying the potassium level in the nutrient solution has shown little affect on transplant growth as well; however, sev eral studies suggest that fast growing species are more affected by potassi um nutrition than slow growing species. Increases in the nutrient supply to vegetable transplants often decreases the root/shoot ratio, yet several st udies suggest than plants with relatively large root systems suffer less tr ansplant shock. It is becoming more apparent that nutritional requirements of transplants are dependant upon climate and end use.