An IPM Program for Managing Fungal Leaf Blight Diseases of Carrot in New York

Abstract

Fungal leaf blight diseases caused by Cercospora carotae and Alternaria dauci occur annually on processing carrot in New York, with growers applying up to eight fungicide sprays to manage these diseases. An integrated pest management (IPM) program involving the use of a 25% disease incidence threshold to prompt the first fungicide application and timing subsequent sprays by monitoring for increases in disease severity and weather forecasts in conjunction with a 10- to 14-day spray interval was evaluated in grower fields in 1997 and 1998. The IPM plots, compared with the grower plots, required two to six fewer fungicide applications but showed no yield reduction. From 1999 to 2004, the IPM program was validated and the effect of crop rotation and carrot cultivar susceptibility also were assessed. Carrot plants growing in fields with 2-year or longer crop rotation intervals reached the 25% disease incidence threshold later in the season and required fewer fungicide applications. The less-susceptible carrot cultivars also reached the 25% disease incidence threshold later, required fewer fungicide applications, and were less severely diseased than more susceptible cultivars. Validation of the IPM program in New York showed that both fungal leaf blights can be managed effectively using a 25% incidence threshold to prompt the first fungicide spray and making the subsequent fungicide applications based on increases in disease severity, weather forecasts, and a 10- to 14-day spray interval.

Growth Manipulation of Slicer Carrots by Foliar-applied Gibberellic Acid in New York

“…Leaf length was evaluated by measuring 20 arbitrarily selected leaves within each plot (10 per row) from the crown to tip on two occasions representing mid and late season in each trial (Table 1). Foliar disease severity was quantified by estimating the percent area affected by Alternaria leaf blight caused by Alternaria dauci and Cercospora leaf blight caused by Cercospora carotae (Gugino et al 2007a(Gugino et al , 2007b on each of 20 leaves within each plot at the end of the season (Table 1). In each year, 30 arbitrarily selected carrot leaves were also collected across each trial.…”

A Three-Year Field Validation Study to Improve the Integrated Pest Management of Hot Pepper

“…The short-term goals of integrated pest management (IPM) are to rally cultural, physical, and biological controls to decrease the frequency of pesticide spraying and prevent the damage caused by crop pests ( Bounds and Hausbeck, 2007 ; Gleason et al, 1997 ). Pest outbreak forecasts can predict the distribution, timing, and amount of the pest ( Bounds et al, 2006 ; Byrne et al, 1997 ; Gugino et al, 2007 ). In order to decide the timing of curative pesticide spraying, one needs to establish a forecasting system that can monitor the current pest population as well as predict pest behavior at least few days into the future in order to prepare for IPM ( Jung, 2010 ).…”

“…Well-designed IPM strategies simplify the application of pesticides while controlling for multiple pests of a host plant ( Gugino et al, 2007 ; Kim et al, 2006 ). We studied an IPM for hot pepper by considering anthracnose, tobacco budworm, and Phytophthora blight ( Kim et al, 2010 ).…”