Effects of EM-calcium spray on Ca uptake, blossom-end rot incidence and yield of greenhouse tomatoes (Lycopersicon esculentum)

Calcium is well known to maintain proper membrane structure and integrity, and plays important roles in crop development and disease control. The exogenous Ca applications are a suitable choice because they improve the calcium nutrient uptake of crops. In this research, tomatoes were selected as plant materials and sprayed with the self-made EM-calcium solutions on different plant organs; aimed at investigating (1) the Ca uptake and forms in tomato fruits with different treatments and (2) the effects of EM-calcium on tomato yield and BER incidence. Results showed that EM-calcium application significantly increased content of Ca pectate, Ca phosphate and carbonate, and water-soluble Ca in tomato fruits, while had no obvious effects on calcium silicate contents; the BER incidence of different EM-calcium treatments was 2.23-13.39% lower compared to that of CK (22.81%); after supplied with EM-calcium, the marketable tomato yield was increased to be the maximum value of 26.67 t/ha; it was also suggested that spraying EM-calcium on tomato leaves or young fruits obtained better results in increasing tomato yields and controlling the BER incidence; based on the observation of Ca accumulation in tomato leaves, roots and stems, it was deduced that foliar-spraying EM-calcium promoted the calcium translocation from the leaves to another organ which needed calcium most. The study conclusions indicated that the preparation of EM-calcium was a successful attempt, which was beneficial for the tomato cultivation and BER prevention.