Keeping late blight out of potatoes is a season long campaign for growers and one that seems to be getting tougher as the years go by, with seven day spray intervals now standard practice, say crop specialists at UK based adjuvant supplier, Interagro.
They point out that with resistance to fluazinam now established in the blight populations and a continuing shift towards more aggressive P. infestans populations, such as 36_A2 and 37_A2, a robust resistance management strategy is essential to safeguard crops and chemistry.
Interagro’s Crusade product was developed to help tackle the practical problems potato growers face, the company says. Crusade is said to be a flexible drift retardant, specifically designed to maximise the performance of blight fungicides by reducing drift and maximising coverage to all parts of the crop canopy.
Reasons why fungicide performance can be improved
According to Interagro, keeping spray intervals tight is a practice that growers have become familiar with – but it isn’t without its challenges when unfavourable conditions can mean spray days are few and far between.
Interagro agronomists point out that drift is the biggest cause of off-target chemical movement and increases the threat to the crop from late blight where it’s not adequately protected.
Strong and weak fungicide actives can have weak spots due to poor coverage, and such weak spots in haulm protection are more likely to be found out, according to Interagro’ crop specialists.
They point out that whilst full crop coverage is vital to prevent scattered infection, the “umbrella-like” structure of the plant canopy – a series of interlocking leaves – makes this very difficult to achieve, they point out.
Leaves are good collectors of vertical moving spray in the upper canopy, but leaves and stems lower down can be very hard to reach, moving the risk of tuber blight to the whole crop.
Interagro specialists say Crusade is a “unique and flexible drift retardant designed for use with all potato blight fungicides throughout the growth of the crop, to help maximise protection and prevent blight infection.“
More information on Crusade can be found here.