single superphosphate per ha for each tonne of target yield is typically required to maintain soil P levels. Using superphosphate also ensures adequate sulfur for the crop.
Lentil crops may respond to zinc, manganese, iron or molybdenum in soils that are deficient in these trace elements. Use liquid injection or solid fertiliser during seeding to correct any likely deficiencies.
Irrigation of lentil is possible, but good drainage is essential because lentil plants do not tolerate waterlogging, particularly during early flowering. Even short periods of waterlogging can result in severe losses. Management requirements for irrigated lentil are the same as for dryland crops, with a greater emphasis on disease control as irrigated crops are more prone to the spread of foliar diseases due to the dense canopy and potentially prolonged leaf wetness after irrigation.
Salinity levels in irrigation water or the soil to be watered must be low. Lentil is one of the more sensitive field crops to salinity—almost as sensitive as green beans (Phaseolus vulgaris), which require irrigation water < 0.7 dS/m for nil yield reduction. A 10 per cent yield reduction is expected if the irrigation water measures 1.0 dS/m.
Some experienced lentil growers in the eastern Mallee regions of Victoria successfully use overhead irrigation. Flood irrigation of lentil crops is not widely practiced in Australia because the risk of yield loss to waterlogging is considered to be high. Nevertheless, irrigation may be economical if the irrigation system allows adequate drainage, there is good quality water available and the rotation with other winter and summer crops is managed well to reduce the risk of disease pressure.
Good weed control is essential because lentils grow slowly during winter and compete poorly against weeds. Weedy lentil crops lose yield, are difficult to harvest and contribute only minimal rotational benefits to subsequent crops.
Avoid sowing lentil in paddocks with a history of severe broadleaf weed problems. Vetches, tares, medics, clovers, wild radish, bedstraw, bifora and self-sown pulses are particularly hard to control in lentil crops. While use of the herbicide tolerant varieties PBA Hurricane XT and PBA Herald XT might increase the herbicide options for weed control over conventional varieties, this does not over-ride the necessity for careful paddock selection and adequate weed control in previous years. Preventing seed set of broadleaf weeds in the year prior to growing lentil is very important.
It is essential to plan your weed control strategy before sowing. Delaying sowing is an option in most areas except the lower rainfall areas (below 350 mm). This strategy can enable several weed kills before sowing. Delayed sowing is practical for shorter season varieties like PBA Blitz and PBA Flash, but not for varieties that require a longer growing season.
Herbicides applied pre-sowing or post-sowing pre-emergent (PSPE), or a combination of both, can control many broadleaf weeds. Most grass weeds can be controlled either pre-emergent or post-emergent, with the exception of those with herbicide resistance.
Diflufenican products and flumetsulam are registered for post-emergent broadleaf weed control in lentil. Some caution is required as some varieties are sensitive to post-emergent herbicides. PBA Hurricane XT and Herald XT have increased herbicide tolerance to applied flumetsulam and residuals of some ‘SU’ and ‘imi’ products. Imazethapyr can be used only on PBA Hurricane XT and Herald XT under APVMA permit PER14369.
Refer to herbicide labels or seek professional advice for optimal weed control before and during the lentil season.
Avoiding herbicide damage
Pre-seeding herbicide applications are often considered safer and more reliable than post-sowing applications, particularly under dry conditions. To ensure weed control in the seeding furrow and to minimise crop damage, a combination of pre and post-sowing applications may be required.
Under adverse seasonal or soil conditions, most post-sowing, pre-emergent herbicides can damage lentil