CRM (COMPARATIVE RELATIVE MATURITY): |
THERE IS NOT AN INDUSTRY STANDARD FOR MATURITY RATINGS SO COMPARING HYBRID MATURITY AND HARVEST MOISTURE RATINGS BETWEEN COMPANIES IS USUALLY DIFFICULT. USE THE CRM RATING TO COMPARE PIONEER HYBRIDS WITH COMPETITIVE HYBRIDS OF A SIMILAR MATURITY AND HARVEST MOISTURE. CRM RATINGS, AND HARVEST MOISTURES, FOR HYBRIDS WITHIN A FAMILY MAY VARY SLIGHTLY, DEPENDING UPON THE LEVEL OF INSECT (ECB AND CRW) INFESTATION. CONVENTIONAL AND STRAIGHT HYBRIDS WITH THE RR2 GENE WITHIN A FAMILY WILL USUALLY BE 1-2 CRMS EARLIER THAN INDICATED, WHEN INSECT INFESTATIONS ARE MODERATE TO HEAVY. ONE CRM DIFFERENCE IS ABOUT ½ POINT OF MOISTURE DIFFERENCE AT HARVEST. |
PHYSIOLOGICAL CRM: |
MEASURES DIFFERENCES IN MATURITY TO ZERO MILKLINE STAGE. TO HELP DECIDE IF A NEW HYBRID FITS YOUR AREA’S GROWING SEASON, COMPARE ITS PHYSIOLOGICAL CRM TO A HYBRID THAT YOU PLANT OR ONE THAT IS SUCCESSFULLY USED IN YOUR AREA. |
GRAIN DRYDOWN: |
COMPARES HYBRIDS OF SIMILAR MATURITY FOR RATE OF MOISTURE LOSS DURING GRAIN DRYDOWN. A HIGHER SCORE INDICATES FASTER DRYDOWN. A LOWER SCORE INDICATES SLOWER DRYDOWN, OR A WIDER OPPORTUNITY FOR SILAGE AND HIGH-MOISTURE CORN HARVEST. |
STRESS EMERGENCE: |
ALL HYBRIDS ARE EXPECTED TO ESTABLISH NORMAL STANDS UNDER AVERAGE SOIL CONDITIONS. STRESS EMERGENCE IS A MEASURE OF THE GENETIC ABILITY OR POTENTIAL TO EMERGE IN THE STRESSFUL ENVIRONMENTAL CONDITIONS OF COLD, WET SOILS OR SHORT PERIODS OF SEVERE LOW TEMPERATURES, RELATIVE TO OTHER PIONEER HYBRIDS. RATINGS OF 7-9 INDICATE VERY GOOD POTENTIAL TO ESTABLISH NORMAL STANDS UNDER SUCH CONDITIONS; A RATING OF 5-6 INDICATES AVERAGE POTENTIAL TO ESTABLISH NORMAL STANDS UNDER MODERATE STRESS CONDITIONS; AND RATINGS OF 1-4 INDICATE THE HYBRID HAS BELOW AVERAGE POTENTIAL TO ESTABLISH NORMAL STANDS UNDER STRESS AND SHOULD NOT BE USED IF SEVERE COLD CONDITIONS ARE EXPECTED IMMEDIATELY AFTER PLANTING. STRESS EMERGENCE IS NOT A RATING FOR SEEDLING DISEASE SUSCEPTIBILITY, EARLY GROWTH OR SPEED OF EMERGENCE. |
DROUGHT TOLERANCE: |
DROUGHT TOLERANCE IS A COMPLEX TRAIT, DETERMINED BY A PLATFORM'S ABILITY TO MAINTAIN YIELD IN LIMITED-MOISTURE ENVIRONMENTS. A HIGHER SCORE INDICATES THE POTENTIAL FOR HIGHER YIELDS VS. OTHER PLATFORMS OF SIMILAR MATURITY IN LIMITED-MOISTURE ENVIRONMENTS. |
HIGH RESIDUE SUITABILITY: |
HS - HIGHLY SUITABLE; S – SUITABLE; MA – MANAGE APPROPRIATELY; X - POORLY SUITED. SUITABILITY RATING BASED ON FIELD OBSERVATIONS AND A WEIGHTED CALCULATION OF GRAY LEAF SPOT, STRESS EMERGENCE, ANTHRACNOSE STALK ROT, NORTHERN CORN LEAF BLIGHT, AND DIPLODIA EAR ROT SCORES. HIGH RESIDUE SUITABILITY RATINGS MAY VARY BY ENVIRONMENT AND GEOGRAPHY. |
TEST WEIGHT: |
HIGHER SCORE INDICATES HEAVIER TEST WEIGHT. |
PLANT HEIGHT: |
9 = VERY TALL; 1 = SHORT. |
MID-SEASON BRITTLE STALK: |
RATINGS DETERMINED BY FREQUENCY AND SEVERITY OF STALK SNAPPAGE AT LOWER TO MIDDLE STALK INTERNODES FROM CONDITIONS USUALLY FAVORED BY RAPID OR OPTIMUM GROWTH. RELATIVE RESPONSE OF HYBRIDS CAN BE AFFECTED BY PLANTING DATE, STAGE OF GROWTH, RATE OF GROWTH, WIND SEVERITY AND OTHER VARIABLES. SCORES DERIVED FROM BOTH NATURAL OBSERVATIONS AND ARTIFICIAL EVALUATION IMMEDIATELY PRIOR TO TASSELING. NOTE: SCORES DO NOT REFLECT SNAPPAGE ENHANCED BY OR DUE TO HERBICIDE INTERACTION. THE USE OF GROWTH REGULATOR HERBICIDES SUCH AS 2,4-D AND DICAMBA CAN INCREASE THE BRITTLE SNAP POTENTIAL OF CORN HYBRIDS. HYBRIDS WITH LOWER BRITTLE STALK RATINGS WILL REQUIRE MORE CAUTION AND HAVE A HIGHER RISK ASSOCIATED WITH THE USE OF GROWTH REGULATOR HERBICIDES. EARLY APPLICATION, PROPER RATES AND APPLICATION METHODS, ALONG WITH BOTH HYBRID AND HERBICIDE SELECTION CAN HELP REDUCE THIS RISK. BRITTLE STALK PRECAUTION: IN AREAS WITH HIGHER POTENTIAL FOR BRITTLE STALK BREAKAGE, GROWERS MUST BALANCE THE RISK OF PLANTING HYBRIDS WITH BRITTLE STALK RATINGS OF LESS THAN 4 AGAINST THE OVERALL PERFORMANCE OF MORE RESISTANT HYBRIDS WITH HIGHER RATINGS. ALL HYBRIDS HAVE A PERIOD OF SUSCEPTIBILITY TO BRITTLE STALK. HYBRIDS WITH BELOW AVERAGE RATINGS MAY HAVE A LONGER PERIOD OF SUSCEPTIBILITY, OR MAY EXPERIENCE MORE SEVERE BREAKAGE RELATIVE TO HYBRIDS WITH HIGHER SCORES DURING PERIOD OF SUSCEPTIBILITY. |
DISEASE PRECAUTION: |
GROWER SHOULD BALANCE HYBRID YIELD POTENTIAL, HYBRID MATURITY AND CULTURAL PRACTICE SELECTION AGAINST THEIR ANTICIPATED RISK OF A SPECIFIC DISEASE AND NEED FOR RESISTANCE. IN HIGH DISEASE-RISK CONDITIONS, CONSIDER PLANTING HYBRIDS WITH AT LEAST MODERATE RESISTANCE RATINGS OF 4 OR HIGHER TO HELP REDUCE RISK. WHEN SUSCEPTIBLE HYBRIDS WITH DISEASE RATINGS OF 1 TO 3 ARE PLANTED IN CONDITIONS OF HIGH DISEASE PRESSURE, THE GROWER ASSUMES A HIGHER LEVEL OF RISK. IF CONDITIONS ARE SEVERE, EVEN HYBRIDS RATED AS RESISTANT CAN BE ADVERSELY AFFECTED. INDEPENDENT OF YIELD REDUCTION, DISEASES CAN PREDISPOSE PLANTS TO SECONDARY DISEASES SUCH AS STALK ROTS. THIS REQUIRES INDIVIDUAL FIELD AND HYBRID MONITORING FOR STALK STABILITY AND TIMELY HARVEST WHEN WARRANTED. |
DISEASE & PEST RATINGS: |
8-9 = HIGHLY RESISTANT; 6-7 = RESISTANT; 4-5 = MODERATELY RESISTANT; 1-3 = SUSCEPTIBLE; BLANK = INSUFFICIENT DATA. |
NORTHERN LEAF BLIGHT CAUTION: |
IN CONDITIONS WHERE NORTHERN LEAF BLIGHT (NLB) RISK IS HIGH, GROWERS SHOULD CONSIDER PLANTING ONLY HYBRIDS WITH AT LEAST MODERATE NLB RESISTANCE RATINGS OF 4 OR HIGHER. |
GIBBERELLA EAR ROT CAUTION: |
RATINGS BASED UPON VISUAL SYMPTOMS AT HARVEST. IF GIBBERELLA EAR ROT HAS CAUSED SIGNIFICANT DAMAGE IN THE PAST, GROWERS SHOULD CONSIDER PLANTING ONLY HYBRIDS WITH AT LEAST MODERATE GIBBERELLA EAR ROT RATINGS OF 5 OR HIGHER. |