Fertiliser
Soils in the ORIA are generally deficient in phosphorus (P), nitrogen (N) and zinc (Zn), therefore fertilisers are applied to compensate. Grower practice is to apply approximately 40kg of P/ha, 3kg Zn/ha, 10kg sulphur (S)/ha and 45kg/ha N. However, these levels may be too high or unnecessary in some instances, particularly N.
There are indications that N might provide some benefit to the crop prior to nodulation. Inspection of nodulation in commercial crops during 1999 and 2000 indicated that active nodulation does not commence until approximately five weeks after sowing. However, high levels of N could also adversely affect nodulation and care should be taken if applying higher rates.
Chickpeas are very efficient at utilising soil P. They secrete organic acids from their roots, which dissolve insoluble sources of P to provide water-soluble P for plant uptake. Hence, sites that have been cropped for several years may have adequate levels of residual P. Studies conducted in the ORIA have indicated that a soil P level of 24mg/kg is sufficient for chickpea production.
It is common practise in the ORIA to apply diammonium phosphate (DAP) at 200-300kg/ha, as it is generally the least expensive form of P fertiliser available. However excess N is applied at this rate. It is now suggested that growers use 3:1 super phosphate/potash at 150-250kg/ha.
Zinc deficiencies have been recorded on crops in the ORIA. The practice of applying Zn (3kg/ha) in the form of zinc monohydrate has been common in recent years. However, build up in soil Zn levels does occur and annual application may not be necessary. Soil levels above 2ppm are generally adequate for most field crops grown on Cununurra clay soils in the ORIA.
Irrigation
The scheduling of crop irrigation is a critical management strategy affecting kabuli chickpea yield and quality. For Kimberley Large and Macarena during the cropping season, eight irrigations are usually required with an inundation period of 8-12 hours. It is suggested that irrigations be timed to coincide with the following stages of growth:
- pre-sowing irrigation
- post emergent
- early growth/vegetative
- 50% flowering
- start of podding
- early podding
- mid podding
- end of podding.
Soil type and seasonal conditions may affect crop growth and development, and consequently, the timing of irrigation at each growth stage. For instance, irrigation may need to be more frequent if temperatures are warmer and when grown on Ord sandy loam, which has a lower water holding capacity when compared to the Cununurra clay.
The development of root and seedling diseases is promoted by waterlogged conditions at sowing, due to watering too early or excessively following sowing. Therefore, sowing must be delayed until the soil moisture conditions are optimum after the pre-sowing irrigation (14 to18 days). Generally, the first post-sowing irrigation is required about 14 to 18 days after sowing (post emergence).
Diseases
Seedling diseases and root rots are the most damaging diseases. It is likely that a complex of Pythium, Fusarium, Phytophthora and Rhizoctonia species causes most diseases. The development of disease can be more severe where the soil remains wet for prolonged periods. Hence, soil moisture at sowing and during crop establishment needs to be monitored to minimise the possibility of waterlogging at this time. It is recommended that seed be treated with P-Pickle T to reduce the risk and impact of disease (see section on Seed Treatment). P-Pickle T is not effective against Phytophthora spp.
Crop rotation is important in managing crop disease. Ideally, chickpea rotation needs to be limited to one year in three to minimise the persistence of fungal pathogens in the soil infecting subsequent chickpea crops. Other crops may act as a host for some fungal pathogens (for example other legumes and possibly some other dicotyledons such as cotton), which needs to be considered when selecting paddocks for chickpea. Chickpea following cereal crops such as maize and sorghum produce the best seed yield and quality.
Insects
The main insect pest in the ORIA is heliothis (Helicoverpa spp.), which can cause severe damage to crops. If present at flowering and early podding, larvae may feed on flowers and developing pods. Once punctured, seed development ceases in young pods and results in yield loss. During mid to late podding, larvae feed on the developing seeds, causing reduced yields and unmarketable seeds.
Generally, it is not recommended to spray for budworm during the vegetative stage, unless significant damage to the crop is evident. Crops need to be checked for budworm twice weekly from the time the crop emerges. Threshold levels for each developmental stage are presented below:
| Growth stage | Threshold (larvae per m of crop) |
|---|---|
| Vegetative | 20-30 |
| Flowering | 5 |
| Podding | 3 (small-medium) to 5 (very small) |
Inter-row cultivation is a cheap and effective method of reducing heliothis levels in chickpea crops, however care is needed to avoid root pruning of the chickpea crop. Cultivation collapses pupal tunnels and prevents the emergence of heliothis moths. Inter-row cultivation can also be useful by reducing weed burden, however pre-sowing weed management is preferred.
Harvest
Approximately two weeks after the final irrigation the crop can be undercut about 2.5cm below the soil surface. The soil requires some residual moisture to allow effective undercutting. The crop can be harvested between 7 to 14 days following undercutting, depending on weather conditions, crop biomass and crop moisture. The crop is ready to harvest when the stems and pods are light brown and the seed feels hard and rattles within the pod. At this stage, the seed moisture content should be around 15%. Harvesting at lower seed moisture content (13%) increases the susceptibility of the seed to physical damage during and after harvest.
Markets
The Ord River District Co-operative Ltd. markets kabuli chickpea produced in the ORIA. The product mainly supplies domestic markets in Australian capital cities where it is sold as whole seed in specialty shops and, in larger volumes, to hommus, falafel and dip manufacturers. The processing market requires varieties with specific 'after cooking' flavour. Macarena and Kimberley Large varieties provides these quality attributes and are also sold to high value international markets in Italy and surrounding Mediterranean countries.
Acknowledgements
This web page has been developed from research supported by the Grains Research and Development Corporation (GRDC). We also thank staff at the Department of Agriculture and Food, Western Australia, and the Ord River District Co-operative Ltd, Kununurra for their input in the preparation of this information.