evaluate the joint effect of Alternaria (A. solani L.) leaf spot, (Orobanche ramosa L.) on naturally infected tomato plants (Lycopersicon esculentus L.)

Abstract

This research work was conducted in winter season on 2006-2007, at the Agricultural Research Corporation Experimental Farm- Shambat. The experimental Design was RCBD with three replications. All cultural practices and application of treatments were done properly. The purpose of this research was to evaluate the joint effect and strategy of Alternaria (A. solani L.) leaf spot, with Halouk (Orobanche ramosa L.) on naturally infected tomato plants (Lycopersicon esculentus L.) variety Peto 86. Both diseases casual agents annually attack this popular variety of tomato, severely and reducing its quality and quantity. Fungicide Ivory M 72 W.P dose (10 gm/l) was used to combat Alternaria, hand removal was used to combat Orobanche ramosa L., and neem leaf powder 8 dose (10 gm/l) as soil amendment method was used to compare it with hand pulling method. This experiment revealed that simultaneous attack by Alternaria solani L. and Orobanche ramosa L. to tomato plants mentioned, can be controlled effectively by simultaneously using fungicide Ivory M72 W.P at rate of 10 gm/l and hand pulling for Orobanche ramosa L. . It was also clear that the earlier is the spray against Alternaria solani L. before onset of the disease, is the better in the protective effect. It seem that Neem leaf powder, other than its adverse effect on Orobanche ramosa L., has simultaneous antifungal effect against Alternaria solani L. or since Neem leaf powder was applied as soil amendment it could have improved tomato health and its resistance to Alternaria solani L. Finally we feel Orobanche ramosa L. deprived tomato of its nutrients, so badly that it was rendered weaker to Alternaria solani L. attack. All treatments gave significant results compared to untreated, whether Orobanche ramosa L. or Alternaria solani (see results table). No and weight of tomato fruits obtained were highly significant that positive effects of Ivory M 72 W.P at the rate of 10 g/l and Hand pulling of Orobanche ramosa L., and Neem leaf powder were clearly reflected on the observed field.